Work machines, such as loaders, are used in many industries, such as farming and construction, and are used to perform many different jobs within each industry. For example, farmers use loaders to move soil as well as lift hay bales and other heavy items. A single machine is able to perform many different tasks by having different tools that can be releasably attached to the loader lift arms. This means that the user need not buy several machines, each dedicated to a particular task, but may use one or a few, multipurpose machines instead. This clearly has advantages in terms of cost.
However, the task of attaching and detaching tools from loaders can be difficult. The tools are typically heavy, weighing upwards of a couple of hundred pounds, and manually maneuvering them is a physically demanding job. The means of attachment itself can also be cumbersome and difficult to operate, particularly during periods of cold weather when the operator will be wearing heavy gloves.
Various arrangements have been proposed to address this problem. For example, U.S. Pat. No. 5,466,113 and U.S. Pat. No. 7,001,137 both disclose latching arrangements for locking a tool to the lift arms of a work machine.
U.S. Pat. No. 5,466,113 discloses the use of a carrier or support, pivotally coupled to the lift arms using a pin, the carrier including two pairs of brackets for receiving an elongate, horizontal locking bar that is used to attach the tool to the carrier. The locking bar can be reciprocated along a horizontal axis between a locking position and an unlocking position. Corresponding brackets on the tool can be positioned in a space between the brackets on the carrier so that in the locking position the locking bar extends through the apertures in the brackets on both the carrier and the tool, thereby securing the tool to the carrier. The elongate locking bar allows the tool to be simply detached and attached to the carrier from one side only.
U.S. Pat. No. 7,001,137 discloses a similar system to that described in U.S. Pat. No. 5,466,113, but with a hydraulic cylinder for moving the locking bar between the locked and unlocked positions.
These systems are effective and user friendly, but suffer from limited durability of the carrier when the carrier is subjected to significant loads in use.